<?php

/**
 * PHPTAL templating engine
 *
 * PHP Version 5
 *
 * @category HTML
 * @package  PHPTAL
 * @author   Kornel Lesiński <kornel@aardvarkmedia.co.uk>
 * @license  http://www.gnu.org/licenses/lgpl.html GNU Lesser General Public License
 * @version  SVN: $Id:$
 * @link     http://phptal.org/
 */
class PHPTAL_Tokenizer {

  private $regex, $names, $offset, $str;
  private $current_token, $current_value;

  function __construct($str, array $tokens) {
    $this->offset = 0;
    $this->str = $str;
    $this->end = strlen($str);

    $this->regex = '/(' . str_replace('/', '\/', implode(')|(', $tokens)) . ')|(.)/Ssi';
    $this->names = array_keys($tokens);
    $this->names[] = 'OTHER';
  }

  function eof() {
    return $this->offset >= $this->end;
  }

  function skipSpace() {
    while ($this->current_token === 'SPACE')
      $this->nextToken();
  }

  function nextToken() {
    if ($this->offset >= $this->end) {
      $this->current_value = null;
      return $this->current_token = 'EOF';
    }

    //if (!preg_match_all($this->regex, $this->str, $m, PREG_SET_ORDER, $this->offset)) throw new Exception("FAIL {$this->regex} at {$this->offset}");
    if (!preg_match($this->regex, $this->str, $m, null, $this->offset))
      throw new Exception("FAIL {$this->regex} didn't match '{$this->str}' at {$this->offset}");

    $this->offset += strlen($m[0]); // in bytes

    $this->current_value = $m[0];
    $this->current_token = $this->names[count($m) - 2]; // -1 for usual length/offset confusion, and minus one extra for $m[0]

    return $this->current_token;
  }

  function token() {
    return $this->current_token;
  }

  function tokenValue() {
    return $this->current_value;
  }

}
